To the traditional laws of association, Bain added two of his own: the law of compound association and the law of constructive association. The law of compound association states that associations are seldom links between one idea and another. Rather, an idea is usually associated with several other ideas either through contiguity or similarity. When this is true, we have a compound association. With such associations, sometimes experiencing one element, or perhaps even a few elements, in the compound will not be enough to elicit the associated idea. However, if the idea is associated with many ele- ments and several of those elements are present, the associated idea will be recalled. Bain thought that this law suggested a way to improve memory and recall: “Past actions, sensations, thoughts, or emo- tions, are recalled more easily, when associated either through contiguity or through similarity, with more than one present object or impression”.
With his law of constructive association, Bain inserted a creative element into associationism in much the way Hume had done. In discussing his law of constructive association, Bain said, “By means of association the mind has the power to form new combinations or aggregates different from any that have been presented to it in the course of experi- ence” (Bain, 1855/1977a). In other words, the mind can rearrange memories of various expe- riences into an almost infinite number of combi- nations. Bain thought that the law of constructive association accounted for the creativity shown by poets, artists, inventors, and the like.